Note: Descriptions are shown in the official language in which they were submitted.
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METHOD FOR APPLYING A FOAMED FIBER INSULATION
Field of the Invention
The present invention relates to a method for
insulating an existing or newly constructed structure in
which a mixture of a foamed adhesive material and a fibrous
insulation material are caused to adhere the structure
without the need for a retaining means to hold the mixture
in place.
Background Information
Methods for supplying fibrous insulating materials by
injection under air pressure provide a generally economical
method of insulating a desired space. Such methods are
economical at least partly because relatively inexpensive
fibrous materials such as cellulose, or mineral fibers,
fiberglass and the like can be used, as described, for
example, in U.S. Patent No. 4,487,365 issued December 11,
1984, to Sperber; U.S. Patent No. 4,530,468 issued July 23,
1985, to Sperber: U.S. Patent No. 4,712,347 issued to
Sperber; and U.S. Patent No. 4,768,710 issued September 6,
1988, to Sperber and also because of the relative speed
with which the insulation can be injected under air
pressure compared with the installation of batt-type
insulation.
There are two primary methods for supplying fibrous
insulating materials by injection under air pressure. In
the first, insulation particles mixed with adhesive are
inserted into the space between the outer and inner walls
of the structure. Since it is desirable to "blow in" the
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insulation particles and adhesive mixture prior to the
construction of the inner walls, a retaining means, as
described, for example, in U.S. Patent No. 4,712,347, by
Sperber, issued December 15, 1987, is typically used to
retain temporarily the insulation between the wall framing
until the inner wall can be constructed to act as a
permanent retaining barrier.
The process of blowing-in fibrous insulation has at
least one major drawback. The process typically produces
insulation with non-homogeneous density. The nonhomogeneity
is caused both by the later portions of blown-in insulation
impacting and compacting the first portions of blown-in
insulation and by the settling of the fibers over time. In
general, compacted or densified fibrous insulation has a
lower insulating capacity compared to less dense or
uncompacted fibrous insulation. Although an adhesive can
be used to assist in maintaining the loft of fibrous
insulation, as described in U.S. Patent Nos. 4,487,365:
4,530,468: and 4,712,347 above, the adhesive may have
insufficient time to set, cure or dry before impaction from
succeeding portions of insulation occurs and may have
insufficient strength to withstand the force of impact from
succeeding portions of blown-in insulation. Additionally,
the adhesive by itself may not be sufficiently spread or
mixed with the fibers to provide the desired separation of
the fibers.
In the second method for supplying fibrous insulating
materials by injection under air pressure, lofted fibers of
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insulation are mixed with a foam to provide a blown-in
fibrous insulation which has a substantially homogeneous
density, providing for uniformity of insulation, as
disclosed in U.S. Patent No. 4,768,710. The lofted
insulation fibers are created by the mixture of
substantially dry fibrous particles with pressurized air.
Similarly, the foam is created by the mixture of a foaming
agent with pressurized air. The foam and lofted fibers are
then introduced into the mixing chamber of a nozzle.
Although not discussed in the '710 patent, a single mixing
hose is typically connected to the nozzle. The inside
diameter of the mixing hose is greater than that of the
nozzle outlet. In the mixing chamber and mixing hose, the
foamed material is mixed with the lofted fibers so that the
foam maintains the loft or the desired spreading of the
insulation fibers relative to each other. The length of
mixing hose can be approximately two feet. The mixture of
fibers and foam material is carried under pressure away
from the mixing hose into the desired space, but without
any velocity, where the foam maintains the desired loft or
spreading of the insulation fibers to achieve a uniform
density of the insulation over time.
Like the first method, the apparatus and method of
U.S. Patent No. 4,768,710 has a significant limitation.
The apparatus does not eject the foam/insulation mixture
with sufficient velocity to cause the mixture to adhere to
a surface, even though an adhesive material has been
incorporated into the mixture. Rather, as in the first
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method, placement of the mixture requires the use of some
means to retain temporarily the insulation between the wall
framing until the inner wall can be constructed to act as
a permanent retaining barrier.
In contrast to loose fibrous insulation, insulation
comprising a solid "foam" is used in some applications.
Although fibrous material can be incorporated into such
foam as crystallization sites, fillers, reinforcements
and/or pacifiers, as described in U.S. Patent No. 4,402,892
issued September 6, 1983, to Helser, it is the solid foam
itself, rather than the fibers, which produces the
insulation effect. To enable such insulation to fill a
void, it is first produced in a fluent form and then cured
or dried to form the solid foam. Thus, the fluent foam must
be capable of substantial solidification into a permanent
body. Materials which are capable of this solidification
such as a cementitious material, as described in the Helser
patent, or resin materials as described in U.S. Patent No.
4,103,876 issued August 1, 1978, to Hasselman, Jr. et al.
and U.S. Patent No. 4,135,882 issued January 23, 1979, to
Harkness et al. are typically more expensive than fibrous
insulation materials. Furthermore, many solid foam
insulation materials require relatively expensive and
time-consuming additional steps to accomplish curing or
drying, such as a heating step.
U.S. Patent No. 4,447,560 issued May 8, 1984, to
Piersol describes forming a fibrous sheet by agitating a
mixture of a foamable solution and a slurry of binder-
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coated insulation fibers to homogeneously suspend the
fibrous slurry. The present invention differs from the
subject matter of the Piersol patent in several important
respects. First, unlike the Piersol patent, the present
invention does not utilize a slurry of fiber and binder
materials but requires the use of pressurized air to
provide spreading of insulation fibers to achieve a desired
degree of fiber "fluffiness." Second, the foam material
desired herein is already in its agitated state when it is
mixed with the fibers. Third, the insulation mixture of
the present invention is directly sprayed under pressure
into a formed cavity at a building construction site; there
is no formation of a batt-type insulation or a standard
sheet of fibrous material. Finally, there is no step of
heating for drying purposes after the insulation material
is located in the cavity.
A common denominator for insulating methods using
either blown in fibrous insulation or solid foam or batt-
type insulation is the substantial construction labor and
materials required to provide a structure to accommodate
the insulation. For example, for loose fibrous insulation,
a building contractor first typically constructs a cavity
for the insulation by attaching a temporary retaining
structure to a series of studs spaced at regular intervals
in the wall. After the fibrous insulation is inserted into
the cavity, a permanent retaining structure, such as
drywall, is nailed to the studs. Expensive fire retardant
drywall is sometimes used to decrease fire danger. To
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provide a wall amenable to finishing such as painting or
wallpapering, a drywall finisher must fill and finish not
only the seams between the drywall panels but also each of
the innumerable nail indentations in the drywall. Not
surprisingly, this process is time and labor intensive and
substantially increases already high construction expenses.
Insulating methods using either solid foam or batt
type insulation are even more expensive than loose fibrous
insulation. A building contractor must not only perform
the above-noted construction steps (with the exception of
the erection of a temporary retaining means) to accommodate
the insulation but also use must incur additional expenses
required to manually install the insulation in a wall
cavity. For example, batt-type insulation is typically
inserted into a cavity and then stapled to the surrounding
studs. Additionally, solid foams require relatively
expensive and time-consuming steps to accomplish curing or
drying, such as a heating step.
Based on the foregoing, there exists a need for method
for applying insulation that reduces the costs associated
with present methods of installing insulation. More
specifically, there is a need for a method of applying
insulation that substantially eliminates, the need for the
construction of a retaining structure. It would be
particularly advantageous to have a method to apply
insulation in which the insulation could be molded,
preferably substantially simultaneously with its
application to desired shapes and textures. Further, there
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is a need for an insulating method that, in appropriate
circumstances, eliminates the need for a permanent
retaining structure, such as drywall. Stated another way,
there is a need for a method of insulating that produces an
insulating structure that can also serve as a wall,
ceiling, or like structure which can be painted,
wallpapered or otherwise textured. Further, in the
situations in which the use of drywall or similar surfaces
is appropriate, there is a need for a method of insulating
that reduces the costs associated with the hanging and
finishing of drywall. Additionally, there is the further
need for an insulating method that reduces the costs
associated with providing a fire resistant structure.
Moreover, there is a need for a method of insulating that
can reduce costs associated with painting the structures
that presently overlay the insulating layer in a building.
Finally, there is a need for an insulation which can not
only adhere to a wall but also can have its strength and
insulating properties altered to correspond with the needs
of specific applications.
Summary of the Invention
The present invention provides a novel method for
insulating buildings that substantially eliminates the need
for erecting a retaining structure to accommodate the
insulation. The method includes the steps of applying
foamed fiber insulation, a foamed adhesive binder mixed
with insulation particles, while in a flowable state to a
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desired surface. The foamed fiber insulation adheres to
the surface and, while in the flowable state, may be molded
to a desired shape and texture. In another embodiment, the
foamed fiber insulation may be substantially simultaneously
shaped as the foamed fiber insulation is sprayed to the
desired thickness and the need for an additional step to
contour the insulation eliminated. The foamed fiber
insulation subsequently cures to form a substantially rigid
layer which retains the desired shape and texture. The
foamed fiber insulation adheres and may be applied to
surfaces such as wood, metal, masonry, concrete, stucco, or
urethane. Moreover, the foamed fiber insulation can be
applied to surfaces having varying orientations, such as
wall and ceilings. Accordingly, a wide variety of surfaces
may be insulated without the need for the construction of
a temporary or permanent retaining structure, thereby
substantially reducing construction costs.
The ability of the foamed fiber insulation to be
molded into any desired shape or texture while in the
flowable state permits the resulting rigid layer to be used
as a wall, ceiling or similar structure that can be
finished without the installation of drywall or some other
type of wallboard, as is required by existing insulation
methods. After the foamed fiber insulation is contoured to
the desired shape and texture and cures to a substantially
rigid state, it may be painted, wallpapered, or left
unfinished, as desired.
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If drywall is to be employed, it may be cemented to
the exposed surface of the cured foam fiber insulation.
This obviates the need for drywall to be nailed to studs
and simplifies and reduces the expense of the drywall
finishing process by eliminating the presence of nail
indentations in the drywall. Consequently, the drywall
finisher need only f ill and finish the seams between the
drywall panels.
The compression and tensile strengths of the
insulation layer may be selected by adjusting the mixture
of foamed adhesive material and insulation particles. The
compression and tensile strengths and "R" rating of the
layer are directly proportional to the density of the
insulation particles in the layer and inversely
proportional to the density of foamed adhesive material.
In other words, the greater the density of insulation
particles and the lower the density of foamed adhesive
material, the greater the compression and tensile strengths
of the layer and the "R" rating. Accordingly, the
insulation layer may have a lower density of insulation
particles and a greater density of foamed adhesive material
in areas requiring less strength and a lower "R" rating,
such as ceilings, and a higher density of insulation
particles and a lower density of foamed adhesive material
in areas requiring greater strength and a higher "R"
rating, such as walls which will frequently contact people
or heavy objects. The amount of insulation particles may
also be attenuated to produce a foamed fiber insulation
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with few insulation particles that can be applied to the desired
surface for dust suppression and the like.
The foamed fiber insulation may include additives such
as a dye to produce a substantially rigid insulation layer of a
desired color and thereby eliminate the need to paint the
insulation. Additionally, the foamed fiber insulation may
incorporate a fire retardant material to produce a fire retardant
insulation layer. The ability of the insulation to itself be
fire resistant reduces the need for expensive fire retardant
drywall or other measures to reduce flammability.
Also disclosed is an apparatus and method useful in
providing a fibrous insulation mixture which is sprayed under
pressure into a desired space where the mixture adheres to
surfaces of the space. In this manner, no retaining means
is necessary to retain the mixture in the desired space. The
mixture has a substantially homogeneous density of fibrous
insulation so as to provide for uniformity of insulation.
Substantially dry fibrous particles are mixed with
pressurized air to produce lofted fibers which are introduced
into the mixing chamber of the nozzle and then into a
mixing hose. A foaming agent and adhesive are mixed with
pressurized air to create a foamed adhesive material which
is also introduced into a mixing chamber of a nozzle and then
into a mixing hose. In the mixing chamber and mixing hose, the
lofted fibers are substantially mixed with the foamed
adhesive material so that the foam maintains the
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loft or the desired spreading of the insulation fibers
relative to each other. The mixture of fibers and foamed
adhesive material is introduced from the mixing hose into
a spraying assembly consisting of a plurality of hoses of
different inner diameters with the inner diameter of each
hose being less than the inner diameter of the nozzle. The
mixture of the fibers and foamed adhesive material is
ejected from the spraying assembly with a velocity
sufficient to cause the mixture to adhere to a surface
while substantially reducing separation between the fibers
and foam and adhesive material and continuing to maintain
the desired loft or spreading of the fibers to achieve
uniformity of the insulation. Because of the presence of
the foamed adhesive material, the lofted fibers in the
desired space are able to withstand the impact from
subsequent application of the mixture and are able to
maintain the loft or separation of fibers in spite of the
weight of insulation material above. To attain the
necessary velocity to cause the mixture to spray and adhere
to the desired surface, the inner diameters of the spraying
hoses are decreased in a stepwise fashion to produce a
venturi effect. The mixture components dissociate when the
mixture is introduced into a hose having a smaller inner
diameter and therefore smaller cross-sectional area of
flow. Each spraying hose is of a length sufficient to
allow substantial remixing of the mixture of fibers and
foamed adhesive material in the hose after a decrease in
inner diameter.
a
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After the mixture has been sprayed into the desired
space, the adhesive material, after drying, acts to
maintain the loft or separation of fibers even when the
foam or liquid portion dries or dissipates. In this way,
the dried, sprayed-in insulation maintains its insulation
capacity by virtue of the fibers rather than the continued
presence of a foam. The foam also acts to spread the
adhesive for desired mixing with the fibers.
With regard to the nozzle itself, it includes a
conduit that carries the foamed adhesive material and which
tapers at the nozzle portion where partial mixing of the
fibers and foamed adhesive material occurs. This
configuration is important in preventing back flow of
material into the conduit, particularly whenever the flow
of materials is.discontinued for a time by shutting off the
pressurized air.
Brief Description of the Drawings
Fig. 1 is a schematic cross-sectional view of the
lofted fibers and foamed adhesive insulating mixture
applied to a cinder block wall.
Fig. 2 is a schematic cross-sectional view of the
lofted fibers and foamed adhesive insulating mixture
sprayed on a cinder block wall.
Fig. 3 is a schematic cross-sectional view of the
lofted fibers and foamed adhesive insulating mixture being
contoured with a trowel after application on a cinder block
wall.
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Fig. 4 is a schematic cross-sectional view of the
lofted fibers and foamed adhesive insulating mixture sprayed on
a cinder block wall using a second spraying hose equipped with
the trowelling plate.
Fig. 5 is a schematic cross-sectional view of the
lofted fibers and foamed adhesive insulating mixture being
contoured using the second spraying hose equipped with the
trowelling plate.
Fig. 6 is a schematic cross-sectional view of the fully
cured lofted fibers and foamed adhesive insulating mixture with
drywall cemented to its exterior surface.
Fig. 7 is a schematic cross-sectional view of the fully
cured lofted fibers and foamed adhesive insulating mixture
applied to a ceiling and wall.
Fig. 8 is a perspective view of a structure
illustrating the hose apparatus used to apply the insulation to
a structure. Figure 8 is shown in conjunction with Figure 1.
Fig. 9 is a cross-sectional view of the hose apparatus
shown in Fig. 8.
Detailed Description of the Preferred Embodiment
The present invention relates to a method and structure
for insulating surfaces in existing or newly constructed
buildings using foamed fiber insulation, a mixture of insulation
particles and a foamed adhesive material, to form an insulating
layer that adheres to the surface, thereby avoiding the need for
a retaining means to hold the foamed fiber insulation in place.
i a
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2149~4~
Referring to Fig. 1, a layer of foamed fiber
insulation 10 of a desired density and thickness adheres to
a cinder block wall 12. The foamed fiber insulation 10 is
a mixture of a foamed adhesive material 14, which includes
a foam and an adhesive material, and insulation particles
16. Suitable foams must be able to maintain the loft or
spreading of the insulation particles 16 during and after
application. Presently known foams that are capable of
this include detergents. The adhesive material may be any
foamable adhesive such as polyvinyl acetate, ethylvinyl
acetate, animal glues, bentonite based adhesives, plaster
and the like. The insulation particles 16 may be any
insulating particle known in the art including rock wool,
fiberglass, cellulose, wood fiber, or combinations thereof.
The above components are mixed and then applied while
in a flowable state to the cinder block wall 12 by any
suitable technique. The foamed fiber insulation 10 can be
applied by virtually any method that brings the foamed
fiber insulation mixture into contact with the desired
surface, such as spraying or troweling. A temporary or
permanent retaining means may be employed but is not
required as the mixture will readily adhere to and maintain
its desired shape. The mixture can also be applied to any
surface, however oriented, whether the surface is wood,
metal, masonry, concrete, stucco, urethane, or the like.
Accordingly, the mixture may be readily applied to
ceilings, interior walls, floors, attics, exterior walls,
roofs and other surfaces, having substantially any
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orientation. Many other surfaces can also be insulated.
For example, the bulkhead of a ship can be insulated to
prevent condensation. Further, the flowability of the
mixture enables it to insulate void spaces, such as those
surrounding pipe cases, wiring and air ducts, and
electrical boxes, many of which are hard to reach or
difficult to insulate with other methods.
The formed fiber insulation can also be applied to a
surface and then separated from the surface before it
cures. Afterwards, when the layer of foamed fiber
insulation has cured, it can then be attached to the
original surface or to another surface of substantially the
same shape as the original surface. In this manner,
insulation can be created for surfaces before the surfaces
are in place in a structure or for surfaces remotely
located from the foamed fiber insulation. For example,
insulation can be created for piping that has not yet been
installed in a building or, if the piping has been
installed, the insulation can be constructed remotely from
the building site.
Referring to Figs. 2 and 3, the ability of the mixture
to form an insulation layer of desired shape and texture is
illustrated. In Fig. 2, the foamed fiber insulation 18 is
sprayed onto a cinder block wall 20 to a desired thickness.
While still in the flowable state, the layer of foamed
fiber insulation 18 is molded into a desired shape and
texture by troweling and rolling. For example, when the
foamed fiber insulation is applied to a flat roof, it can
i u:
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be molded so that it has a shape which promotes drainage.
As the material is molded, the foamed adhesive material 22
rises to the surface to form a smooth surface with few
exposed insulation particles 24. When cured, the foamed
fiber insulation 18 retains the desired shape and thickness
and the exposed layer of adhesive material 22 forms a
protective coating over the insulation particles 24.
The moisture in the foamed fiber insulation 18 cures
in the ambient atmosphere, without the necessity of heating
or other drying procedures. The cure rate is inversely
proportional to the moisture content of the foamed fiber
insulation 18, which is typically about 16% to 18% and
primarily attributable to the amount of adhesive material
employed. When cured, the foam dissipates leaving a
substantially rigid layer of insulation particles 24
encapsulated in the adhesive material 22. The adhesive
material 22 maintains the loft or separation of insulation
particles even after the foam has dissipated. The cured
layer has a substantially homogeneous density of insulation
particles 24 so as to provide a uniformity of insulation.
Referring to Figs. 4 and 5, a process to mold the
surface of the foamed fiber insulation 26 substantially
simultaneously with its application is depicted. In Fig.
4, foamed fiber insulation 26 is sprayed onto a surface 28
by a spraying apparatus 30 mounting a trowel 32. As shown
in Fig. 5, when the foamed fiber insulation 26 has reached
a desired thickness, the flat metal face 34 of the trowel
32 is moved in a back-and-forth motion to mold the surface
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of the foamed fiber insulation 26 into a desired shape and
texture. The spray of foamed fiber insulation 26 is
typically not stopped during molding so that the deposition
and molding steps occur substantially simultaneously.
The smooth exterior surface of the cured foamed fiber
insulation 26 permits it to be finished in the same manner
as a conventional well, e.g., it may be plastered,
wallpapered, painted, stuccoed, sprayed with acoustic
materials, or left as is. The exterior surface may be
molded to produce a flat surface suitable for the
attachment of wallboard, such as drywall or paneling, or
wallpaper. In addition to the above-described molding
techniques, a form having a rigid, flat surface, such as a
sheet of particle board or plywood, may be used as a form
to provide such a flat surface. The form may be either
removed or left on the surface, as desired.
Referring to Fig. 6, wallboard 36, such as drywall,
can be cemented to the exterior surface 38 of the cured
layer of foamed fiber insulation 40 adhering to wall 42.
Any cement known in the art suitable for use with
wallboards may be used. Preferably, the cement used has a
different chemical composition from the adhesive used in
the foamed fiber insulation 40. The wallboard 36 may be
finished as desired after the cement has dried
sufficiently. The finishing process is simplified by the
avoidance of nail indentations in the wallboard which must
typically be finished. Similarly, with respect to exterior
walls to which the foamed fiber insulation 40 has been
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applied, exterior surfaces such as stucco can be applied or
exterior structures like aluminum siding can be attached.
Referring to Fig. 7, the density and thickness of the
foamed fiber insulation 44, 54 may be varied with the type
of surface being insulated. The compression and tensile
strengths and "R" rating of the layer of foamed fiber
insulation 44, 54 are directly related to the density of
insulation particles 46 and inversely related to the
density of foamed adhesive material 48. In other words,
the greater the density of insulation particles 46 and the
lower the density of foamed adhesive material 48, the
greater the compression and tensile strengths and "R"
rating of the layer 44, 54. Accordingly as illustrated by
Fig. 7, the insulation layer 44, 54 may be less dense in
areas requiring less strength and/or a lesser "R" rating,
such as ceilings 50, and more dense in areas requiring
greater strength and/or a greater "R" rating, such as walls
52, which frequently contact people or heavy objects.
The thickness of the layer of foamed fiber insulation
44, 54 also varies with the type of surface to be
insulated. The thicker the layer of foamed fiber insulation
44, 54, the greater the compression and tensile strength
and "R" rating of the layer. A layer 44, 54 with a
thickness of .25 inches has been found suitable in many
instances. However, layers of up to six feet have
presently been achieved.
The foamed fiber insulation may include a variety of
additives to impart desired properties to the insulation.
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For example, a dye may be added to produce a layer of
foamed fiber insulation of a desired color which does not
require painting. Fire retardant materials may be added to
produce a fire retardant foamed fiber insulation layer.
Typically, a fire retardant adhesive is~combined with a
fire retardant insulating particle to achieve the fire
retardant foamed fiber insulation. Known fire retardant
adhesives include bentonite based adhesives and sodium
silicate based adhesives. Known fire retardant insulating
materials include mineral fibers, fiberglass, vermiculite,
and perulite (an expanded sodium silicate). Additionally,
accelerators can be added to the foamed fiber insulation to
speed the transition from the flowable state to the rigid
state by increasing the rate at which moisture evaporates
from the foamed fiber insulation after application.
Suitable accelerators include non-flammable solvents like
alcohol.
The foamed binder may also be used for dust
suppression on surfaces prior to activities such as
painting. To act as a dust suppressant, the amount of
insulation particles in the foamed fiber insulation mixture
is attenuated to produce foamed fiber insulation with few
insulation particles. The mixture is then applied to the
desired surface where it encapsulates the dust particles on
the surface and provides a clean, smooth surface.
An apparatus and method for mixing the foamed adhesive
material with lofted fibrous insulation particles and
spraying the mixture into a cavity to fill the cavity with
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fibrous insulation having a substantially homogeneous
density is shown in Figs. 8 and 9. As used herein, "spray"
means to provide a mixture of foamed adhesive material and
lofted fibrous insulation at a sufficient velocity to allow
the mixture to substantially adhere to a surface while
substantially reducing separation of the mixture. The
apparatus used for mixing the lofted fibrous insulation and
foamed adhesive material is disclosed in U.S. Patent No.
4,768,710 to Sperber, entitled "Fibrous Blow-In Insulation
Having Homogeneous Density."
Referring to Figs. 8 and 9, a nozzle 60 includes a
mixing chamber 62, a first conduit 64, and a second conduit
66. The first conduit 64 has a first entrance port 68 and
a first exit port 70. The first exit port 70 communicates
with the mixing chamber 62. The first entrance port 68 of
the first conduit 64 is preferably connected to a hose or
pipe 72 for introduction through the entrance port 68 of
fibrous particles as described below. The second conduit
66 has second and third entrance ports 74, 76 controllable
by first and second valves 78, 80, respectively. Connected
to the second and third entrance ports 74, 76 are feed
lines 82, 84 for introduction of foaming agent and adhesive
material and pressurized gas, respectively. The second
conduit 66 has a second exit port 86 communicating with the
mixing chamber 62. In the region of the second conduit 66
near the second exit port 86, the second conduit 66 is
expanded to be located outwardly of the first conduit 64,
preferably surrounding the first conduit 64 as a collar.
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The second conduit 66 tapers towards the first conduit 64
at the mixing chamber 62. The second conduit 66 preferably
contains one or more baffles or obstacles 88 to assist in
foam production. The mixing chamber 62 is attached to a
mixing hose or mixing pipe 92 for completing the mixing of
the lofted fibers of insulation and foamed material and
directing the insulation material. Based on economics, the
most preferred mixing hose length is about two feet, though
the longer the mixing hose 92, the more uniform the mixture
of insulation particles and foamed adhesive materials. The
mixing hose or mixing pipe 92 further includes a first
ejection port 90.
To spray the mixture of fibrous lofted insulation
particles and foamed adhesive material, it is necessary to
increase the -velocity of the mixture when it is ejected
from a second ejection port 94. Since the increase of the
velocity of the fibrous lofted insulation particles and/or
foamed adhesive material in the first and/or second
conduits, respectively, will prevent optimal mixing of the
particles and material, the velocity of the particles and
material in the first and second conduits must remain at a
level below the velocity necessary to cause spraying of the
mixture. The spraying assembly 96 therefore increases the
velocity of the mixture by decreasing the cross-sectional
area of flow.
In a preferred embodiment the spraying assembly 96
consists of two separate interconnected hoses 100 and 102
connected either to each other or the mixing hose 92 by a
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connecting means 104, such as a clamp and/or duct tape,
with each spraying hose having a smaller inner diameter
than the preceding hose and no spraying hose having an
inner diameter equal to or greater than the inner diameter
of the mixing hose 92. In the preferred embodiment, the
inner diameter of the first ejection port 90 and mixing
hose 92 is approximately 2.5 inches, the first spraying
hose 100 is approximately 2 inches and the second spraying
hose 102 is approximately 1.50 to approximately 1.75
inches. As shown in Fig. 9, the inner diameters of the
hoses are decreased in a step-wise fashion for the reason
that the mixture of fibrous lofted insulation particles and
foamed adhesive material was observed to separate whenever
there is any reduction in the cross-sectional area of flow
of the mixture. When the inner diameter was reduced from
approximately 2.5 inches to approximately 1.75 inches
through the use of one spraying hose, the insulation
particles and foamed adhesive material were too dissociated
to apply a uniform mixture of the particles and material to
the desired surface. When the desired reduction was
accomplished in two spraying hoses, the spraying assembly
96 was found to apply a uniform mixture of the particles
and material to the desired surface. Based on these
observations, it appears that the degree of separation is
directly proportional to the degree of reduction. In other
words, it appears that the larger the reduction in cross-
sectional area of flow, the greater the dissociation of the
insulation particles from the foamed adhesive material.
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The gradual reduction of the cross-sectional area of flow
in two stages causes an initial separation of the mixture
components, followed by a gradual remixing, followed by a
second separation and a second remixing. At the end of the
second spraying hose 102, there is sufficient mixture and
sufficient velocity to cause the foamed fiber insulation to
spray. To insure sufficient remixing of the mixture
components following a decrease in cross sectional area,
each spraying hose should have a length of at least about
one foot, though the longer the hose, the more uniform the
mixture of insulation particles and foamed adhesive
material. Based on economics, the most preferred spraying
hose length is about two feet. An overall hose length of
up to 30' - 40' has been used in many applications. As
will be known and understood by those skilled in the art,
the number, inner diameters, and lengths of spraying hoses
may vary depending upon the desired velocity and/or desired
degree of separation of the mixture components and/or
volume of foamed fiber insulation that is to be applied per
unit of time (the greater the volume per unit of time, the
larger the diameter of the spraying hoses).
The manner of using the nozzle 60 and spraying
assembly 96 and of production and placement of insulating
material 106 will now be described. A foaming agent and
adhesive are introduced through the first line 82 and
through the second entrance port 74 into the second conduit
66, with the rate of flow being controlled by the first
valve 78. Any of a number of foaming agents well known in
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the art can be used. Foamable adhesives such as polyvinyl
acetate, ethylvinyl acetate, animal glues and the like can
also be used. A pressurized gas, such as air, is introduced
through the second line 84 and through the third entrance
port 76 at a rate controlled by the second valve 80.
Inside the second conduit 66, the pressurized air mixes
with the foaming agent and adhesive materials to produce a
foam and adhesive material which moves through the second
conduit 66. The baffle or obstacle 88 can be used to
assist in producing foam. The foam and adhesive material
in its foamed state moves through the first exit port 86 of
the second conduit 66 and into the mixing chamber 62 and
then into the mixing hose 92.
Substantially dry, lofted fibrous particles which have
been lofted by mixing with pressurized air are introduced
through the first entrance port 68 into the first conduit
64. The fibrous material can be any fiber well known in
the art including mineral fibers, recycled paper and
fiberglass. The lofted fibers and pressurized air move
through the first conduit 64 and through the first exit
port 70 of the first conduit 64 into the mixing chamber 62
and then into mixing hose 92.
In the mixing chamber 62 and mixing hose 92, the foam
and adhesive material in its foamed state substantially
mixes with the lofted fibers. The tapered area of the
second conduit 66 assists in preventing back flow of
mixture into the conduits, particularly the second conduit
66. Such back flow can occur, for example, when the flow
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of insulation mixture through the nozzle 60 is stopped. If
the flow of the mixed fibers and foamed adhesive material
were permitted back into the second conduit 66, it would be
necessary for the operator to frequently clean out or
unplug the conduit 66 whenever flow of the mixture is
stopped by the operator for some reason, such as.moving the
apparatus to a new cavity for filling with the insulation.
The proportion in which the components are mixed, and
particularly the proportion of liquid foaming material and
adhesive material to pressurized gas and other material, is
preferably adjusted so that the resulting mixture ejected
from the second ejection port 94 has a low moisture content
per volume and has the ability to adhere to a desired
surface when sprayed.
The mixture of fibers and foam and adhesive material
is introduced under pressure from the mixing hose 92 into
the first spraying hose 100. As shown in Fig. 9, the
mixture components separate when the cross-sectional area
of flow is decreased. The mixture components are substan-
tially remixed when they enter the second spraying hose 102
and the cross-sectional area of flow is decreased a second
time. As before, the mixture components separate when the
cross-sectional area of flow is decreased and are substan
tially remixed by the time the mixture is sprayed from the
second ejection port 94.
As shown in Fig. 8, the mixture of fibers and foamed
adhesive material 106 which is sprayed from the second
ejection port 94 is directed to and received in an area 107
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where insulation is desired. In a typical application, the
mixture is directed into the cavity of a typical stud-
construction wall 108 whereby the foamed insulation can be
made and installed at the construction site. Since the
present invention has the ability to spray the mixture of
fibers and foamed adhesive material, the mixture may be
used to install insulation in any other desired cavity,
however oriented, including without limitation ceiling and
floor cavities. As depicted in Fig. 1, the foamed adhesive
material 10 is used to maintain loft or spreading of the
insulation fibers 16 relative to each other. The material
10 maintains such loft or spreading of fibers even when it
is impacted by subsequent applications of the mixture
ejected from the second ejection port 94 and maintains loft
or separation of fibers in spite of the weight of in-
sulation material above.
After the mixture has been placed in the desired area
107 as depicted in Fig. 8, the mixture may be sculpted into
any desired shape or texture by, for example, the use of a
trowel. The moisture in the mixture dries in the ambient
atmosphere, without the necessity for application of heat
or other drying procedures. With the drying of the
moisture, the material 106 dissipates leaving only the
fibrous particles 16 and adhesive which maintained the
fibrous particles in a desired, spread state.
In light of the above discussion of the preferred
embodiment, a number of advantages of the present invention
are apparent. First, the present invention substantially
WO 93/03854 PCT/US92/06690
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reduces the costs associated with present methods of
installing insulation. In appropriate cases, it eliminates
the needs for constructing a cavity, erecting a retaining
structure, and painting the exterior surface of the wall
and reduces the labor and materials required to finish
drywall and fireproofing of the walls. Second, the unique
flowability of the present invention eliminates voids in
hard-to-reach places, reducing air infiltration and energy
costs. Third, the present invention provides an inexpensive
method to retrofit existing buildings which often possess
inadequate insulation. Fourth, a sprayed-in fibrous
insulation is provided which results in substantial
uniformity of insulation, i.e., substantially homogeneous
density. Although a foam is used, it does not have to be
used to create loft or to create air pockets, but rather is
used to maintain a previously-established loft between
fibrous particles. Indeed, the foam itself eventually
dissipates leaving lofted fibrous particle insulation.
Fifth, the foamed insulation of the present invention can
be made and installed on the job or construction site.
Sixth, because the insulation is sprayed in rather than
being a batt-type insulation, the insulation does not need
to be extensively handled. Seventh, because the foam is
used only to maintain an already-created loft and is not a
structural component of the insulation, at least in the
long-term, the foam can be relatively dry, also
contributing to rapid drying of the insulation in the
desired space without the requirement for application of
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heat. Eighth, as opposed to a permanent foam insulation,
the sprayed-in fibrous insulation uses relatively
inexpensive materials such as recycled paper, mineral
fibers or fiberglass and is easy to apply, conforming
naturally to obstacles such as wiring, pipes and the like.
Ninth, a tapered nozzle portion of the present invention
reduces or prevents the flow of foamed insulating material
back into the conduit that carries the mixture of foaming
material and adhesive. As a consequence, this conduit does
not become plugged with fiber material. Tenth, unlike prior
art methods of "blowing in" fibrous insulation, the mixture
of foamed insulation applied by the present invention
adheres to the surfaces of the desired cavity and no
temporary retaining means is required to retain the
insulation during installation. Eleventh, unlike the prior
art, the present invention may be used to fill any desired
cavity with insulation, including, for example, not only
walls but also floors and ceilings. Finally, the sprayed-
on insulation of the present invention may, before drying,
be sculpted into any desired shape or texture by, for
example, the use of a trowel.
Although the present invention has been described with
reference to certain embodiments, it should be appreciated
that further modifications can be effected within the
spirit and scope of the invention.
